The present invention relates to a convertible tandem axle arrangement and method wherein a single drive tandem axle arrangement can be converted to a dual drive, tandem axle arrangement, or vice versa.
Tandem axle arrangements for truck tractors are typically provided with either a single drive axle and a single tag axle (referred to as a 6×2 arrangement) or with dual drive axles (referred to as a 6×4 arrangement). Single drive tandem axle arrangements tend to have lighter weight, provide for better fuel economy, lower installation cost, and offer improved reliability over dual drive tandem axle arrangements. They are mostly used in highway applications.
Dual drive tandem axle arrangements tend to be more versatile than single drive tandem axle arrangements and, consequently, single drive tandem axle arrangements tend to have low resale value because it is difficult and expensive to convert, them to dual drive tandem axle arrangements.
Most tag axles have a different profile and use different suspension and wheel equipment than the drive axle of the tandem axle arrangement. In a conversion of a single drive tandem axle arrangement to a dual drive tandem axle arrangement, not only must the entire original tag axle be replaced with the new drive axle, ordinarily much or all of the suspension and wheel equipment must be replaced with new equipment. It is desirable to provide a tandem axle arrangement that can be conveniently converted from a single drive tandem axle arrangement to a dual drive tandem axle arrangement. It is particularly desirable to provide a tandem axle arrangement that permits the conversion without the need to replace the entire axle arrangement, suspension equipment, and wheel equipment.
In the single drive axle arrangements, the drive axle can be provided on a forward axle or a rear axle. However, at take off of a tandem vehicle, weight shifts rearwardly, putting load on the rear axle and taking load off of the front axle. Accordingly, it can be advantageous to provide the drive axle on the rear axle because that arrangement provides improved traction at take off. It is desirable to provide a convertible tandem axle arrangement that has a rear drive axle when used as a single drive tandem axle arrangement.
According to an aspect of the present invention, a removable carrier housing for a forward tag axle system comprises means for removably mounting the carrier housing to a bowl of a forward tag axle system, a beating arrangement, and a shaft supported by the bearing arrangement and extending from a front end of the carrier housing to a rear end of the carrier housing.
According to another aspect of the present invention, a single drive tandem axle arrangement comprises a forward axle system comprising a forward bowl, and a forward carrier removably mounted on the forward bowl and comprising a shaft supported by bearings and extending from a forward end of the forward carrier to a rear end of the forward carrier.
According to another aspect of the present invention, a method of converting a drive axle system between a single drive tandem axle arrangement comprising a rear drive axle a dual drive tandem axle arrangement comprises providing a forward bowl for a forward axle system, mounting one of a geared forward carrier and an ungeared forward carrier on the forward bowl, and removing the one of the geared forward Lanier and the ungeared forward carrier from the forward bowl and replacing it with the other one of the geared forward carrier and the ungeared forward carrier.